Buoyancy organic Rankine cycle

In the scope of renewable energy, we draw attention to a little known technique to harness solar and geothermal energy. The design here proposed and analyzed is a conceptual hybrid of several patents. By means of a modified organicRankinecycle, energy is obtained utilizing buoyancy force of a working fluid. Based on thermodynamic properties we propose and compare the performance of Pentane and Dichloromethane as working fluids. Theoretical efficiencies up to 0.26 are estimated for a 51 m (Pentane) and 71.5 m (Dichloromethane) high column of water in a regime below 100 °C operation temperature. These findings are especially relevant in the scope of distributed energy systems, combined cycle plants, and low-temperature Rankinecycles.

Highlights

We are currently simulating the conditions of the working fluid as it goes through the cycle. We aim to understand how BORC actually differs from the conventional Rankine cycle and establish a TS diagram associated with a BORC generator. We are also working on a reduced scale prototype.

Furthermore, there is also one aspect we would like to point out, which is related to the context in which the project has been conducted: we would like to stress that one of the main reasons this project has been successful is the inherent interdisciplinary environment established in our young University (UFABC is just 5 years old). We have a department-less organization structure. The realization of the project has only been possible because we had daily contact with engineers, chemists and physicists ranging several kinds of expertise, and most of the interaction has been easy going, unpretentious, informal, cafeteria-like conversations.

Further information:

We are currently simulating the conditions of the working fluid as it goes through the cycle. We aim to understand how BORC actually differs from the conventional Rankine cycle and establish a TS diagram associated with a BORC generator. We are also working on a reduced scale prototype.

Furthermore, there is also one aspect we would like to point out, which is related to the context in which the project has been conducted although it could be that this is not REGI’s main focus (anyhow one might consider this relevant): we would like to stress that one of the main reasons this project has been successful is the inherent interdisciplinary environment established in our young University (UFABC is just 5 years old). We have a department-less organization structure. The realization of the project has only been possible because we had daily contact with engineers, chemists and physicists ranging several kinds of expertise, and most of the interaction has been easy going, unpretentious, informal, cafeteria-like conversations.